Guide and crimp-locating means in electrical connectors and method and apparatus for making same



May 12, 1970 J. s. COSTELLO ETAL 3,512,123

GUIDE AND CRIMP-LOCATING MEANS IN ELECTRICAL CONNECTORS AND METHOD ANDAPPARATUS FOR MAKING SAME Filed Dec. 22, 1966 2 Sheets-Sheet 1 3,512,123IN ELECTRICAL CONNECTORS 2 Sheets-Sheet 2 OR MAKING SAME J. S. COSTELLOETA!- AND METHOD AND APPARATUS F GUIDE AND CRIMP-LOCATING MEANS May 12,1970 Filed Dec. 22, 1966 Zlx United States Patent US. Cl. 339-276 9Claims ABSTRACT OF THE DISCLOSURE An electrical connector is providedwith tapered surface means along the internal surface of a dielectricsleeve and at the entrance to a ferrule defining funnel means to guide aconductive portion of an insulated conductor means within the ferrule.Groove means are provided in an exterior surface of the dielectricmember about a central portion of the ferrule to define crimplocatingmeans for locating the crimping dies of a crimping tool in properrelationship along the ferrule so that an effective crimp can be made.

This invention relates to electrical connectors and more particularly toelectrical connectors having guide and crimp-locating means and a methodof making same.

Electrical connectors are used in large quantities for terminatingelectrical Wires and for making electrical connections. One drawback ofpresent day electrical connectors is that no guide means is provided toeifectively guide the conductive portions of electrical wire means intocrimping sections of the electrical terminals. Another drawback is thatno crimp-locating means is provided on the electrical connectors toproperly locate crimping-die means relative to the crimping sections.

It is therefore desirable to have on electrical connectors guide meanson the interior surface of an insulation support member adjacent acrimping section of the electrical terminal in order to guide theconductive portion of wire means into the crimping section so that theconductive portion can be crimped within the crimping section. It isalso desirable to have on electrical connectors crimplocating means toproperly position crimping-die means relative to the crimping section sothat a proper crimp can be effected to provide an excellent mechanicaland electrical connection.

An object of the invention is to provide an electrical connector havingguide means to guide a conductive position of wire means into a crimpingsection of the electrical connector.

Another object of the invention is the provision of crimp-locating meanson an electrical connector to properly position crimping-die meansrelative to a crimping section of the electrical connector.

A further object of the invention is to provide an electrical connectorwith. guide means to guide a con ductive portion of Wire means into acrimping section of the electrical connector and crimp-locating means onthe electrical terminal to properly position crimping-die means relativeto the crimping section of the electrical connector.

An additional object of the invention is the provision of an electricalconnector having an insulation support section to accommodate insulationof wire means to be crimped in the crimping section.

A still further object of the invention is the provision of a method offorming guide and crimp-locating means on an electrical connector.

Other objects and attainments of the present invention will becomeapparent to those skilled in the art upon "ice a reading of thefollowing detailed description when taken in conjunction with thedrawings in which there are shown and described illustrative embodimentsof the invention; it is to be understood, however, that theseembodiments are not intended to be exhaustive nor limiting of theinvention but are given for purposes of illustration in order thatothers skilled in the art may fully understand the invention and theprinciples thereof and the manner of applying it in practical use sothat they may modify it in various forms, each as may be best suited tothe conditions of a particular use.

The foregoing and other objects are achieved by a preferred embodimentof an electrical connector which comprises connection section means forelectrical connection to a conductive member, crimping-section means forcrimping onto a conductive portion of electrical wire means, sleevemeans having a first section carrying the crimping-section means and asecond section for engagement with insulation of the electrical wiremeans, guide means on an interior surface of the second section forguiding the conductive porton of the electrical wire means into thecrimping-section means, and crimp-locating means on the first sectionfor positioning crimping die means relative to the crimping-sectionmeans.

In the drawings:

FIG. 1 is a perspective view of an electrical connector;

FIG. 2 is a longitudinal cross sectional view of FIG. 1;

FIG. 3 is a perspective view of an alternative embodiment;

FIG. 4 is a longitudinal cross-sectional view of FIG. 3;

FIG. 5 is a perspective view of another embodiment;

FIG. 6 is a longitudinal cross-sectional view of FIG. 5;

FIG. 7 and 8 illustrate an apparatus for forming a sleeve for theelectrical connector of FIGS. 1 and 2; and

FIG. 9 illustrates apparatus for forming a sleeve for the electricalconnector of FIGS. 5 and 6.

Turning now to FIGS. 1 and 2, there is illustrated an electricalconnector EC which comprises a metallic part 1 and a dielectric part 2.Metallic part 1 inludes a lug 3 and a ferrule 4. Lug 3 has an opening 5therein so that the electrical connector can be connected to aconductive member thereby in accordance with conventional electricalconnection techniques. Lug 3 can however take any suitable form toeffect an electrical connection with another electrical condutivemember. The ferrule 4 is a sleeve and defines a crimping section inwhich a conductive portion of an electrical wire means is crimped.Serrations 6 are formed on the interior surface of ferrule 4 in order toincrease the tensile between ferrule 4 and the conductive portion of theelectrical Wire means as well as to score the conductive portion tobreak down the oxide coating on the conductive portion to increaseelectric conductivity. The entrance of ferrule 4 has a beveled surface7.

Metallic part 1 is susceptible to mass production by automatic machineryand is conveniently formed by shaping a sheet metal blank or strip of asuitable electrically-conductice metal such as brass, bronze, or thelike in successive forming steps. The metal is sufficient- 1y hard andresilient to impart to the crimping section a spring-like character, yetit is sufiiciently malleable to permit cold forging or crimping of thecrimping section onto a conductor means to provide an excellentelectrical and mechanical connection.

Dielectric part 2 is a suitable plastic material such as, for example,polyvinyl chloride, nylon or the like which is susceptible tocold-forming techniques. Dielectric part 2 is a sleeve and includes abrst section 8 and a second section 9. First section 8 has acircumferential groove 10 which is centrally located with respect toferrule 4 and defines crimp locating means in which die means of acrimping tool are disposed to properly locate the die means relative toferrule 4 so that a proper crimp can be effected on the conductiveportion of the electrical wire means to obtain an excellent mechanicaland electrical connection. Groove 10 has sufiicent width to extend alonga sufficient length of ferrule 4.

Second section 9 includes a first portion 11 and a second portion 12.First portion 11 is frusto-conical in configuration and second portion12 is cylindrical in configuration so that electrical connector EC canaccommodate the insulation of electrical wire means. An annularprojection 13 is located at the juncture of first section 8 and secondsection 9 of dielectric part 2. The dimension of annular projection 13is such that the inside surface of first portion 11 is tapered andmerges with beveled surface 7 to define a substantially constant taperedsurface therebetween thereby providing funnel or guide means toeffectively lead the conductive portion of electric wire means intoferrule 4. Annular projection 13 also serves to limit the movement offerrule 4 within first section 8 of dielectric part 2 so thatcircumferential groove 10 is properly positioned relative to ferrule 4.

Electrical connector ECa illustrated in FIGS. 3 and 4 is similar toelectrical connector EC of FIGS. 1 and 2 except that second section 9aof dielectric part 2a of electrical connector ECa has a substantiallyconstant outside diameter therealong. It is to be noted however thatfirst portion 11a of second section 9a includes an inner surface offrusto-conical configuration which merges with beveled surface 7a offerrule 4a thereby defining a substantially constant tapered surfacebetween first portion 11:: of dielectric part 2a and the entrance toferrule 4a of metallic part 1a to provide the funnel means to permit theready insertion of the conductive poriton of the electrical wire meansinto ferrule 4w.

Electrical connector ECb illustrated in FIGS. 5 and 6 is directed to anelectrical connector to splice the ends of electrical Wire meanstogether. As can be discerned, ferrule 4b is similar to ferrules 4 and4a except that ferrule 4b is made as a ferrule having two ferrulesections in which respective ends of conductive portions of electricalwire means are crimped. The ferrule sections of ferrule 4b are separatedby spaced indents 14 which act as a stop means to limit the movement ofthe conductive portions of the electrical wire means withing the ferrulesections. Dielectric part 2b is similar to dielectric part 2a with firstportion 11b having tapered surfaces merging with beveled surfaces 7b ofthe ferrule sections of ferrule 4b to provide the guide means to guidethe conductive portions of the electric wire means within the ferrulesections of ferrule 4b. Circumferential grooves 10b are also locatedover respective ferrule sections to provide crimp-locating means for theferrule sections. Annular projections 13b lock ferrule 4b in positionWithin dielectric part 2b. Second sections 9b of dielectric part 2b mayhave a configuration similar to first portion 11 and second portion 12of the dielectric part of electrical connector EC of FIGS. 1 and 2.

Turning now to FIGS. 7 and 8, there is illustrated a method andapparatus for forming dielectric part 2 of electrical connector EC. Theapparatus in FIGS. 7 and 8 comprise mold parts 15 and 16 each having aprojection 17, beveled surfaces on each side of projection 17, a taperedsurface 19 and straight surfaces 20, 20' all of which are semi-circularin cross section since each of mold parts 15 and 16 constitute one halfof mold M.

A movable compound ram 21 includes a first ram member 22 and a secondram member 23. First ram member 22 is a rod that snugly fits within anopening 24 of second ram member 23 and each ram member is movable withrespect to each other. The inner end of 4 first ram member 22 has ablind hole 25. The inner end of second ram member 23 has a reducedsection 26 and a stop surface 27. A movable ram 28 comprises acylindrical section 29, a tapered section 30, a straight section 31, apushing surface 32 and a stop surface 33.

In operation, mold parts 15 and 16 of mold M are spaced from each otherand rams 21 and 28 are positioned so that a tubular member 34 ofsuitable plastic material of proper length is placed within open mold Monto first ram member 22. Mold parts 15 and 16 are brought intoengagement to form mold M and are held in a closed position byconventional means. Rams 21 and 28 are moved toward each other byconventional driving means so that reduced section 26 snugly and tightlymates with straight surfaces 20' and stop surface 27 engages mold parts-15 and 16 thereby limiting the movement of ram 21 within mold M butcontinuous pressure is applied to ram 21 to maintain it in thisposition.

Ram 28 continues to move within mold M with tapered section 30 engagingtubular member 34 thereby causing tubular member 34 to be increased indiameter as ram 28 moves inwardly. Ram 28 continues to move within moldM until cylindrical section 29 bottoms in blind hole 25, pushing surface32 pushes against an end of tubular member 34 and stop surface 33engages mold parts 15 and 16. The section of ram 28 between pushingsurface 32 and stop surface 33 fits snugly within straight surfaces 20'.

The action of ram 28 moving within mold M causes tubular member 34 to bemoved into engagement with tapered surfaces 19 and straight surfaces 20by tapered section 30 and straight section 31 to form first portion 11and second portion 12 of dielectric part 2.

With ram 21 being held in position so that the inner end of reducedsection 26 is in engagement with the other end of tubular member 34, theengagement of pushing surface 32 of ram 28 with the one end of tubularmember 34 as ram 28 is being moved inwardly causes the material oftubular member 34 to flow into beveled surfaces 18 which forms thecrimp-locating means and to flow into the area created by the inner endof ram member 22 and tapered section 30 of ram 28 thereby formingannular projections 13 at the juncture of first section 8 and secondsection 9 of dielectric part 2 and a tapered surface which merges withbeveled surface 7 which form a substantially constant tapered surfacetherebetween to define the guide means.

Mold M is opened and rams 21 and 28 are positioned so that the newlyformed dielectric part can be removed therefrom. After dielectric part 2has been formed by the apparatus in FIGS. 7 and 8, ferrule 4 of metallicpart 1 is inserted in first section 8 of dielectric part 2 to formelectrical connector EC of FIGS. 1 and 2. The inside diameter of firstsection 8 is such so that ferrule 4 is held therein by frictiontherebetween. The completed electrical connector is now ready to becrimped onto an electrical wire means with the guide means effectivelyguiding the bared conductive portion of an electrical wire means intoferrule 4 and the crimp-locating means properly locating crimping-diemeans to crimp ferrule 4 onto the conductive portion of the electricalwire means. Second section 9 of dielectric part 2 may be crimped ontothe insulation of the electrical wire means to provide strain relief.

The mold to form dielectric part 2a for electrical connector ECa ofFIGS. 3 and 4 is the same as the mold to form dielectric part 2 exceptthat tapered surfaces 19 and straight surfaces 20 have the samediameter.

FIG. 9 illustrates mold Ma to form dielectric part 2b of FIGS. 5 and 6.Mold Ma includes mold parts 35 and 36. Each of mold parts 35 and 36includes on the interior surface spaced projections 37, beveled surfaces38 on each side of spaced projections 37 and straight surfaces 39.

Spaced projections 37, beveled surfaces 38 and straight surfaces 39 aresemi-circular in cross section.

Compound rams 40 are insertable within mold Ma and include first rammembers 41 and second ram members 42. Ram members 41 are snugly disposedin openings 43 of ram members 42 so that ram members 41 are movablerelative to ram members 42 and relative to each other. Ram members 41include rounded-nose sections 44, tapered sections 45 and cylindricalsections 46. Ram members 42 include reduced sections 47 and stopsurfaces 48.

In operation, mold parts 35 and 36 are spaced from each other and rams40 are positioned so that a tubular member 49 of suitable dielectricmaterial and of proper length with ferrule 4b therein can be placedwithin mold Ma. Mold parts 35 and 36 are closed and held by conventionalmeans; rams 40 are simultaneously moved within the mold by conventionaldriving means. As rams 40 move within mold Ma, ram members 41 positionferrule 4b so that the ferrtfle sections thereof are properly positionedrelative to projections 37 by means of roundednose sections 44 beingpositioned within the ferrule sections of ferrule 4b and taperedsections 45 engaging the beveled surfaces of the ferrule sections.Reduced sections 47 fit snugly in straight surfaces 39 and the innerends of the reduced sections of ram members 42 engage respective ends oftubular members 49 as rams 40 are being driven inwardly thereby applyingpressure to the tubular member toward the center thereof causing thematerial of tubular member 49 to flow into beveled surfaces 38 to formthe crimp-locating means and to flow into the areas between the ends offerrule 4b and tapered sections 45 to form annular projections 13b andtapered surfaces so that the inner surface of tubular member 49 istapered on each side of the ferrule and these tapered surfaces mergewith the beveled surfaces of ferrule 4b which form substantiallyconstant tapered surfaces therebetween to define the guide means. Rams40 are moved out of mold Ma and mold parts 35 and 36 are moved apart sothat electrical connector ECb can be removed from the mold.

The formation of tubular member 49 into dielectric part 2b by mold Maand rams 40 forms a completed connector with ferrule 4b locked intoposition within dielectric part 2b by annular projections 13b. A smallamount of material of tubular member 49 may flow into spaced indents 14but this will not impair the formation of the crimp locating means byprojections 37 and beveled surfaces 38. If desired, spaced projections37 may be a solid projection thereby eliminating inner beveled surfaces38 so that the groove formed by the single projection will besubstantially constant in diameter throughout and the flow of materialinto indents 14 will then occur. A continuous groove along substantiallythe entire length of ferrule 4b will still perform the function oflocating crimping die means relative to the ferrule sections of ferrule4b because each side of the groove will properly locate the crimping diemeans relative to the crimping sections of ferrule 4b. Ribs may beformed partially around the first section of the dielectric part insteadof being formed entirely therearound as preferred.

The formation of the crimp-locating means and guide means in the plastictubular member by molds M and Ma and associated .rams is accomplishedonly by the application of pressure on the rams thereby subjecting theplastic tubular member to a cold-forming operation.

The formation of dielectric part 2a of FIGS. 3 and 4 and 2b of FIGS. 5,6, and 9 may be a two-step operation instead of a one-step operation.This is accomplished by placing within the tubular members of dielectricmaterial to form dielectric parts 2a and 2b a rod of constant diameterwithin the tubular members and ram members would engage the ends of thetubular members to first form the crimp-locating means. The rods wouldbe replaced by suitable ram members to then form the guide means Withinthe tubular member in the case of dielectric 6 part 2a, and, in the caseof dielectric part 2"b, ferrule 4b and ram members 41 would be used inthe second operation to form annular projections 13b and the guidemeans.

After formation of dielectric part 2a of FIGS. 3 and 4, second section9a can be subjected to controlled expansion to expand this section toany desired diameter within the limits of expansion of the material.This would also be true with respect to dielectric part Zb of FIGS. 5and 6. i

From the foregoing, there has been disclosed a unique and novelelectrical connector having formed on the dielectric part thereof guideand crimp-locating means in a one-step cold-forming operation and acompleted electrical connector for splicing wires together as a completeelectrical connector provided with guide and crimplocating means in aone-step cold-forming operation.

It will, therefore, be appreciated that the aforementioned and otherdesirable objects have been achieved; however, it should be emphasizedthat the particular embodiments of the invention, which are shown anddescribed herein, are intended as merely illustrative and not asrestrictive of the invention.

The invention is claimed in accordance with the following:

1. An electrical connector for mechanical and electrical connection toinsulated wire means comprising, in combination, a metallic part and adielectric part, said metallic part comprising a ferrule, said ferrulehaving an inside surface provided with a beveled surface at one end,said dielectric part defining a sleeve comprising a first part and asecond part, said first part being in engagement with said ferrule andsurrounding said ferrule, said first part having groove means disposedalong substantially a central section of said ferrule to definecrimp-locating means to locate crimping-die means to crimp said ferruleonto a conductive portion of said insulated wire means, an annularprojection on an inside surface of said sleeve at the juncture of saidfirst and second parts, said annular projection being disposed adjacentsaid beveled-surface end of said ferrule, said inside surface of saidsecond part having a tapered surface merging with said beveled surfaceto define a substantially constant tapered surface therebetween toprovide guide means to guide said contive portion of said insulated wiremeans into said ferrule.

2. An electrical connector according to claim 1 wherein said groovemeans constitutes a circumferential groove.

3. An electrical connector according to claim 1 wherein said second partincludes a frusto-conical portion and a cylindrical portion.

4. An electrical connector according to claim 1 wherein said second parthas a substantially constant outside diameter.

5. An electrical connector for joining two lengths of insulated wiremeans comprising, in combination, a metallic ferrule and a dielectricsleeve, said ferrule comprising ferrule sections having beveled surfacesat entrances thereto, said sleeve having a first part surrounding saidferrule and second parts extending outwardly beyond said entrances,annular projections at the junctures of said first part and second partsto secure said ferrule in position within said sleeve, said second partshaving tapered surfaces on inside surfaces thereof merging with saidbeveled surfaces to define substantially constant tapered surfacestherebetween to provide guide means to guide conductive portions of saidwire means itno said ferrule sections, and crimp-locating means on saidfirst part defining groove means extending along said ferrule to locatecrimping-die means for crimping said ferrule sections onto saidconductive portions of said wire means.

6. An electrical connector according to claim 5 wherein said groovemeans defines a circumferential groove.

7. An electrical connector according to claim 5 wherein said groovemeans constitutes a circumferential groove disposed over each of saidferrule sections and along a central section of each of said ferrulesections.

8. An electrical connector according to claim 5 wherein said ferruleincludes means to limit the movement of said conductive portions of saidwire means into said ferrule sections.

9. An electrical connector comprising, in combination, metal ferrulemeans and dielectric sleeve means, said ferrule means having a tubularconfiguration and a beveled surface at least at one end thereof, saiddielectric sleeve means having a first section of tubular configurationin which said ferrule means is disposed and a second section extendingaxially outwardly beyond the beveled-surface end of said ferrule means,an interior surface of said sleeve means having projection means inengagement with the beveled-surface end, said projection means having atapered configuration merging with said beveled surface thereby defininga substantially constant tapered surface between the interior surface ofsaid second section adjacent said projection means and an interiorsurface of said ferrule means, and groove means disposed in said firstsection along an exterior surface thereof and being disposedsubstantially centrally of said ferrule means.

References Cited UNITED STATES PATENTS 2,681,440 6/1954 Swengel.

2,774,810 12/ 1956 Ritter 339-223 X 2,958,723 11/ 1960 Logan et al339-276 X 2,981,787 4/ 1961 Brautigam et al. 339-276 X 2,982,808 5/1961Schwester 339-276 X 3,173,989 3/ 1965 Neaderland 339-276 X 3,356,987 12/1967 Gillespie 339-276 X FOREIGN PATENTS 1,347,726 11/ 1963 France.

RICHARD E. MOORE, Primary Examiner J. H. MCGLYNN, Assistant Examiner

